Closing up the risks from sealing and insulating
Sealing and installing insulation has long been a part of construction projects, but has become more important with the desire for greater energy efficiency. Whether the goal is a greener structure or simply a tighter building envelope, properly installed insulation and sealed joints to prevent air infiltration is a key factor.
Sealing and insulating are generally straightforward processes, and as construction tasks go, tend to be seen as low-risk. But both the materials that are used and the nature of how insulating and sealing materials are applied can create hazards for workers. In this article, we’ll review some of the most common issues.
Depending upon the nature of the structure and its use, a variety of insulating materials may be used. The most common include various forms of fiberglass, cellulose, and polystyrene boards. In addition, workers on renovation and demolition projects involving structures built before the 1970s may also encounter insulation made from asbestos.
While fiberglass is generally considered to be a safe material, its thin fibers can create irritation when they come in contact with workers’ skin, eyes, and respiratory tracts. Cellulose can be dusty, and its fibers may be a respiratory irritant. Polystyrene boards don’t present hazards in insulation use but can give off toxic chemicals if exposed to flame or extreme heat.
Another type of insulation used on some projects is spray polyurethane foam (SPF), which contains isocyanates, chemicals that have been linked to work-related asthma. In some settings, polystyrene may also be sprayed as an insulating material. The spraying process may generate styrene, which can cause respiratory irritation and neurological problems. Latex is often used as a sealant and may be sprayed on fiberglass batting. Some workers may have allergies or sensitivities to latex when it contacts their skin or is inhaled.
Asbestos is a naturally occurring mineral fiber that’s no longer used because of its inherent hazards, primarily the fact that it is a recognized carcinogen. Until the 1970s, asbestos fibers were woven into insulation to be used around pipes, in ceiling tiles, and in walls. It was also present in roofing shingles and floor tiles. When materials containing asbestos fibers are cut, sanded, or damaged, they may release those fibers, exposing workers to respiratory hazards.
Protecting workers from exposure to materials
When working with insulation and sealing materials, workers should receive training about both the task and the specific materials that are being used, including any potential hazards. Personal Protective Equipment (PPE) is required for many types of insulation.
When installing or otherwise working with fiberglass insulation, workers should wear long-sleeved shirts, gloves, long pants, and head coverings. Depending upon the task, they may also require eye and respiratory protection. Similarly, the dust produced by cellulose may warrant masks or other respiratory protection, as does latex sealant.
Because SPF creates the potential for exposure to isocyanates and other chemicals, workplaces must take steps to protect workers, starting with engineering and administrative controls. If such controls are impractical or inadequate, PPE such as a respirator with full face mask or a supplied-air respirator may be required.
Permissible exposure and excursion limits for asbestos are available, and steps must be taken to prevent workers from exceeding those levels. Besides PPE such as respirators, work practices that limit the amount of contact may be needed. The worksite should be properly cleaned; for example, sweeping may redistributed the fibers. Workers may also require decontamination to ensure they don’t carry fibers home on their clothing.
Insulating and sealing projects are varied, and the nature of a given task may present additional hazards that must be addressed. For example, if the location of the work is elevated, fall protection may be needed. If it’s in a confined space, additional safeguards may be put into place. Ventilation may be needed to move fumes away from the worksite.
The work may also expose workers to electrical wires and components, plumbing, air handling, and other equipment that may present hazards. A hazard assessment should be performed before work begins so any specific issues can be addressed.